Microfilm storage and retrieval systems presently use old analog technology and because of that, have a number of problems. Cartridge retrieval is done using theoretical values which do not work because of the mechanical variations and tolerances inherent within the alignment of the hardware elements used in the system. The prior art systems are only capable of fixed resolution and fixed window size image scanning. Very primitive fixed thresholding techniques are sometimes used to convert grey levels into binary data. The systems generally have no built-in intelligence for error recovery or self-diagnostics. The reliability of present systems is a main problem. The breakdown of such systems appear to be nearly an everyday affair. Most of the motors are driven using analog logic without any feedback and nearly always employ open loop controls. Primitive belt-driven motion control techniques are commonly used. No velocity profiles are generated or motions monitored. Using existing systems, no optimization is possible for the motion (based on distance to be moved). Inherently, compromised speeds must be picked for both short and long moves. Furthermore, the performance of existing systems appears very poor with limited band width.
Most existing systems accept only particular types of film (24X, 32X ) with many restrictions. Image quality is generally governed by primitive thresholding techniques. Using the prior systems, it is not possible to extract information from the noisy data. There exists no provision for loading the cartridges using software without jeopardizing safety requirements.
In the storage and retrieval unit of the present invention, all the electronics are redone. Digital technology is used throughout and brand new algorithms and theory are used. State-of-the-art technology is used; thus, many capabilities are added. Latest hardware technologies are employed. Software is completely redone with new ideas, new algorithms and in C language. Many of the mechanical subsystems are redesigned. All mechanical subsystems involved in cartridge retrieval are looked into, and a number of improvements are made to improve system reliability and function. The MegaSAR of the present invention is an on-line microfilm jukebox. The system architecture allows for any future expansion or additions. Hardware and software subsystem designs are modular. The system is a closed loop system developed with state-of-the-art technology.